A 6-year-old unvaccinated girl presents with severe paroxysmal coughing spells followed by inspiratory whooping and posttussive vomiting for 3 weeks. Vital signs: BP 98/62, HR 112, RR 38, Temp 37.8°C, SpO2 94% on room air. CBC reveals WBC 18,500/μL with marked lymphocytosis (78%). Chest X-ray shows no infiltrates. She denies fever or rhinorrhea. Which mechanism best explains the lymphocytosis observed in this patient?
- A)Activation of the Gs protein leading to increased cyclic AMP
- B)Direct destruction of ciliated epithelium by endotoxin
- C)Interference with folate metabolism
- D)Suppression of neutrophil oxidative burst
- E)Inhibition of the Gi protein leading to increased cyclic AMPGABARITO
Explicação
Inhibition of the Gi protein leading to increased cyclic AMP is correct. Pertussis toxin ADP ribosylates Gi, which increases cyclic AMP and contributes to impaired immune cell trafficking, resulting in lymphocytosis. The whooping cough and unimmunized status s... Ver explicação completa e trilha adaptativa →